According to some studies, the average global temperature has increased 1.4 degrees Fahrenheit since the 1800's. At the current trajectory of global warming, some of these studies predict that the average global temperature may increase by anywhere from 2.5 to 10.4 degrees Fahrenheit by the year 2100. Much of the global warming phenomenon has been accredited to an imbalance caused by a continual increase in greenhouse gas emissions and a decrease in forestation, which is capable of offsetting such increased emissions. Some greenhouse gasses are predominately emitted through the production and burning of fossil fuels, such as coal, oil and natural gas to meet various energy demands. As the population of the planet continues to grow and many nations become more industrialized, the increased energy demands will create an even greater imbalance likely resulting in a precipitous rise in global temperatures. Very simplistically, one solution to halt the rise in global warming involves a reduction of greenhouse gas emissions, much of which are a by-product of processes utilized to meet today's energy needs.
Many suggestions have been proposed for the development of clean renewable energy to combat global warming by reducing or eliminating greenhouse gas emissions without depleting valuable nonrenewable resources. Some suggestions have explored the use of renewable resources such as biofuels, biomass, geothermal energy, hydroelectricity, solar energy, wave energy and wind energy, each with its own advantages.
The harnessing of wind energy has been shown to be practical in generating power and electricity and is constantly gaining more widespread use throughout the world and in particular in the United States. In 2010, wind energy accounted for approximately 2.3 percent of the electricity generated in the United States, amounting to almost 95,000 megawatt-hours of electricity. This is electricity that would have otherwise likely been generated by burning fossil fuels. Thus, carbon dioxide emissions, one of the most abundant greenhouse gasses, were reduced by approximately 64 million tons. The U.S. Department of Energy has established a goal for the year 2030 to generate 20 percent of the electricity in the U.S. from wind energy. Much of the power from wind energy in the U.S. is currently generated by massive wind turbines clustered on farms throughout the rural U.S. and to a lesser extent offshore. While the wind turbines have proven to be relatively effective, they are quite costly to build and maintain. In order to reach the goal of 20 percent power generation from harnessed wind energy, hundreds of thousands of new wind turbines will need to be put into effect. However, the cost of such a project using today's technology is staggering and may be unattainable. Thus, in order to reach the goal of 20 percent power generation from wind energy, additional methods need to be realized.
Some methods that are being explored propose to capture the wind energy produced by vehicles travelling on a roadway. In several known versions of this method, the wind energy produced by passing vehicles is harnessed via wind turbines provided above ground alongside a roadway, in a median structure between the lanes of a roadway, or on the sides and top of a tunnel, for example. These techniques are demonstrated in U.S. Pat. Nos. 7,525,210, and 7,098,553 and U.S. Patent Application Publication No. 2007/0059097. These known techniques, however, are disadvantageous because they clutter the roadways with unsightly wind turbines, they restrict or constrain views, and they limit other uses of the area surrounding the roadways. Moreover, by their very nature, the wind turbines in these methods must be provided a considerable distance away from the passing vehicles generating the wind energy and thus are inefficient. The wind turbines in the above methods experience less wind than that generated by the passing vehicles, and thus do not achieve optimum performance. Additionally, the little wind that is experienced by the wind turbines in the above methods is not directionally uniform and is difficult to effectively capture, requiring the use of wind turbines that are more complex.
Accordingly, there is a need in the art to provide efficient wind harnessing systems and methods for harnessing the wind energy produced by vehicles passing over a roadway surface without the disadvantages described above.